Launched upon it, there is only one way to keep going, and a thousand ways to fall off. That is the way evolution works, and that is how the natural world as a whole runs itself. The instincts driving the anthill are those that succeeded in the past. The genes that programmed them were selected by particular events in the past. Neither the instincts nor the genes, however, had any way to plan for the future. A major change in the immediate environment, or a mutation of the kind that occurred in Supercolony, could quickly lead to disaster. For a species to continue on in a particular environment indefinitely required precision and luck.
Supercolony had fallen off the tightrope. In this vital way it resembled the great human anthill above and around it. When its end came, it would be at the hands of the moving-tree gods.
25
ON A CLOUDLESS AFTERNOON in late August the denizens of Supercolony, blind to any danger facing them, prepared for the greatest event of their yearly cycle. They were about to hold a mating swarm. It was to be the culmination of all their activities, the central purpose of their existence as a colony. It made possible the immortality of their kind. The season and the weather were right. Two days previously a thunderstorm moving northeast off the Gulf of Mexico had dumped a full two inches of rain on the Lake Nokobee tract. This morning the ground was still moist, and plants wilted by the midsummer drought had begun to regain a little of their springtime turgidity and greenness. The sun heated the soil of the sprawling nest, and humid air weighed heavy and still upon its surface.
At midmorning a biological clock in the brains of the Supercolony ants triggered the nuptial event. Workers by the thousands came pouring out of the entrance holes. They spread over the nest surface, milling about in excited chaos. Within minutes they were joined by a horde of virgin winged queens and males. None flew off. Mating started immediately. Multiple males piled on top of each virgin queen, jostling one another, forcing their way closer to the object of their desire, each struggling to be the one who copulated. Even when one succeeded in joining his genitalia solidly to that of a queen, the tumult around the pair continued. The failed males were frantic. To mate, just once, at this precise time and at this place, was the only purpose for which they existed. Locating a queen a few seconds too late or making less than a do-or-die effort spelled defeat and a childless death.
Winners and losers alike among the males flew away, but only to die. That night thousands of the corpses piled up beneath the porch light of a nearby farmhouse on the Lake Nokobee road. At dawn small birds came to feast on them. Later in the morning the owner, an elderly lady, murmuring "What on God's earth is this all about?," swept the remainder off the porch into the front yard.
Queens, in contrast, had no reason to be desperate. Each one was all but certain to be mated. After copulating with one or more males, they broke off their dry, membranous wings and climbed back down into the nest interior. If their luck held, they would soon join the egg-laying reproductive force of Supercolony.
That would not happen this day, however. Wholly by chance, the gods seen as moving trees had chosen the day and hour of mating to fix the environment. The nuptial frenzy was dying down on the Supercolony nest domes when the divine presence arrived. In one instant there was no sign of the moving-tree gods, but in the next instant they were there, bodies towering into the sky, tree-trunk appendages moving swiftly, their shadows and odors sweeping over the Supercolony nest. There were many of them this time. Large objects floated through the air by their sides. The ground trembled where they stepped. Strange noises descended from above, not like thunder, more like a strong wind blowing through the tree branches.
The apparitions moved on, beyond the eastern reaches of the Supercolony nest area, until a few minutes later no sign of them remained.
An hour later the ants still out on the nest sensed that the gods were coming back. But they did not see the giants this time. Instead they detected a strange and unpleasant odor. The ants were alarmed. They responded to the smell as though it were an alarm pheromone